In the cracking of paraffins to produce olefins, and particularly alpha olefins, a feed stock, for example, a lower paraffin such as ethane or naphtha, is heated to a temperature of at least about 850° C., or from about 900° C. to about 1000° C. In the process, the molecules in the feed stock lose hydrogen and become olefins. This process takes place in the heater coils inside the furnace in the radiant box of the ethylene cracker. The hot gases leaving the furnace are quickly fed to a quench exchanger. The line from the exit of the furnace tubes to the quench exchanger tube sheet or cooling section entrance is a transfer line. Due to the configuration of most plants the transfer line contains an elbow having, for example, about a 90° bend. The transfer line may include a diffuser to transition the diameter of the flow from that of the furnace pipe or tube to the diameter of the tubesheet of the quench exchanger (e.g., the external surface of the quench exchanger). There may also be several sections or fittings in the transfer line so that it may not be a unitary piece of pipe. In the quench exchanger, the gasses are quickly cooled to a temperature below which they will no longer react.